1. Field of the Invention
The present invention relates to a precision-workable aluminum material suitable for forming the substrate of a photoconductor for an electrophotographic copying machine and, more particularly, to a precision-workable aluminum material for forming a photoconductor having excellent properties allowing satisfactory formation of a film thereon and mirror-finish machining, and capable of being finished to form a surface with few minute machining defects.
2. Description of the Prior Art
Recent electrophotographic copying machines are provided with a photoconductor of an improved quality having improved characteristics. The use of photoconductor as a photoconductive material has improved the quality of images formed on the photoconductor remarkably. With such improvements in view, qualitative requirements of substrates for carrying a photoconductive material, such as the body of a photoconductive drum, have become very severe.
To form substrates meeting such severe qualitative requirements, efforts have been made to reduce surface defects in the mirror-finished substrates by forming the substrates of aluminum or an aluminum alloy (which will be designated inclusively as "aluminum material" hereinafter) having a high purity and the least possible content of Fe containing compounds and Mn containing metal compounds. Tools capable of burnishing the surface of aluminum substrates have been developed for finishing the surface of aluminum substrates.
These measures have eliminated surface defects in the substrate attributable to the crystals of Fe containing metal compounds and Mn containing metal compounds contained in an aluminum material forming the substrate. Those measures, however, are unable to eliminate a problem that the surface of the substrate is liable to be roughened by machining. Even the burnishing tool is unable to prevent surface roughening, and any currently available tool is unable to prevent perfectly surface defects including surface roughening in the substrate formed of an aluminum material.